Climate change is a well-known phenomenon all over the globe. The influence of projected climate change on agricultural production, either positive or negative, can be assessed for various locations. The present study was conducted to investigate the impact of projected climate change on rice’s production, water demand and phenology for the state of Bihar, India. Furthermore, this study assessed the irrigation water requirement to increase the rice production by 60%, for the existing current climate scenario and all the four IPCC climate change scenarios (RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5) by the 2050s (2050–2059). Various management practices were used as adaptation methods to analyze the requirement of irrigation water for a 60% increase in rice production. The climate data obtained from the four General Circulation Models (GCMs) (bcc_csm1.1, csiro_mk3_6_0, ipsl_cm5a_mr and miroc_miroc5) were used in the crop growth model, with the Decision Support System for Agrotechnology Transfer (DSSAT) used to simulate the rice yield, phenological days and water demand under all four climate change scenarios. The results obtained from the CERES-Rice model in the DSSAT, corresponding to all four GCMs, were ensembled together to obtain the overall change in yield, phenology and water demand for the 10 years from 2020 to 2059. We investigated several strategies: increasing the rice yield by 60% with current agronomic practice; increasing the yield by 60% with conservation agricultural practice; and increasing the rice yield by 30% with current agronomic practice as well as with conservation agricultural practices (assuming that the other 30% increase in yield would be achieved by reducing post-harvest losses by 30%). The average increase in precipitation between 2020 and 2059 was observed to be 5.23%, 13.96%, 9.30% and 9.29%, respectively, for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5. The decrease in yield during the 2050s, from the baseline period (1980–2004), was observed to be 2.94%, 3.87%, 4.02% and 5.84% for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. The irrigation requirement was predicted to increase by a range of 39% to 45% for a 60% increase in yield using the current agronomic practice in the current climate scenario by the 2050s, for all four climate change scenarios from the baseline period (1980–2004). We found that if we combine both conservation agriculture and removal of 30% of the post-harvest losses, the irrigation requirement would be reduced by 26% (45 to 19%), 20% (44 to 24%), 21% (43 to 22%), 22% (39 to 17%) and 20% (41 to 21%) with the current climate scenarios, namely, the RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 conditions, respectively. This combination of conservation practices suggests that the irrigation water requirement can be reduced by a large percentage, even if we produce 60% more food under the projected climate change conditions.

中文翻译：

---

预测受印度比哈尔邦气候变化影响的水稻生产需水量

气候变化是全球众所周知的现象。可以对不同地点的预计气候变化对农业生产的影响进行评估，无论是积极的还是消极的。本研究旨在调查预测的气候变化对印度比哈尔邦水稻生产、需水量和物候的影响。此外，本研究评估了到 2050 年代（2050 –2059）。使用各种管理实践作为适应方法来分析水稻产量增加 60% 对灌溉水的需求。从四个一般环流模型 (GCM) (bcc_csm1.1, csiro_mk3_6_0、ipsl_cm5a_mr 和 miroc_miroc5) 用于作物生长模型，农业技术转让决策支持系统 (DSSAT) 用于模拟所有四种气候变化情景下的水稻产量、物候天数和需水量。DSSAT 中 CERES-Rice 模型获得的结果，对应于所有四个 GCM，被集合在一起以获得 2020 年到 2059 年 10 年的产量、物候和需水量的总体变化。我们研究了几种策略：增加按照目前的农艺做法，水稻产量提高了 60%；通过保护性农业实践将产量提高 60%；并通过当前的农艺实践和保护性农业实践将水稻产量提高 30%（假设另外 30% 的产量将通过减少 30% 的收获后损失来实现）。对于 RCP 2.6、RCP 4.5、RCP 6.0 和 RCP 8.5，观察到 2020 年至 2059 年的降水平均增幅分别为 5.23%、13.96%、9.30% 和 9.29%。2050 年代，RCP 2.6、RCP 4.5、RCP 6.0 和 RCP 8.5 的产量从基线期（1980-2004 年）分别下降 2.94%、3.87%、4.02% 和 5.84%。到 2050 年代，对于基线期（1980 年至 1980 年至 2050 年）的所有四种气候变化情景，使用当前气候情景中的当前农艺实践，预计灌溉需求将增加 39% 至 45%，产量增加 60%。 2004）。我们发现，如果我们将保护性农业和消除 30% 的收获后损失结合起来，灌溉需求将减少 26%（45% 至 19%）、20%（44% 至 24%）、21%（43到 22%）、22%（39% 到 17%）和 20%（41% 到 21%）与当前的气候情景，即 RCP 2.6、RCP 4.5、RCP 6.0 和 RCP 8.5 条件，分别。这种保护措施的结合表明，即使在预计的气候变化条件下我们生产的粮食增加 60%，灌溉用水需求也可以大幅减少。0 和 RCP 8.5 条件，分别。这种保护措施的结合表明，即使在预计的气候变化条件下我们生产的粮食增加 60%，灌溉用水需求也可以大幅减少。0 和 RCP 8.5 条件，分别。这种保护措施的结合表明，即使在预计的气候变化条件下我们生产的粮食增加 60%，灌溉用水需求也可以大幅减少。